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  <title>Document</title>
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<body>
  <script>
    function Person() {
      this.uname = 'zs'
    }

    var p = new Person()  // {uname: 'zs'}

    console.log(p.uname)

    function fn(obj) {
      obj.uname = 'ls'
    }
    fn(p)

    console.log(p.uname)
  </script>
</body>
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